On Oct 27, 3:16*pm, "Steve N." wrote:
wrote in message

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On Oct 27, 2:37 am, "Steve N." wrote:





"Steve N." wrote in message

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"JIMMIE" wrote in message
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On Oct 26, 10:37 pm, (Doug Miller) wrote:
In article , Sam E
wrote:
If all the loads supplied by that service are 120V loads (e.g.
blender,
toaster, light bulbs, range hood, stereo, TV, computer, etc.) what do
you get
when you divide that maximum power by 120V?

That would be 400A.

Exactly so.

Of course that's only in your imagination since
the math is invalid (120V is obtained by splitting the service into 2
separate halves, each of which is only 24KW).

200A each. Total of 400A of 120V loads -- as you said.

Where in the box can you measure 400 amps? If the panel is controlling
48KW there will be no current on the neutral because the currents will
be balanced. The current that flows through one half of the breaker is
the same current that flows through the other half of the breaker. In
this case what you have is two 200 amp breakers in series. Doug you
have more current coming into the box than going out and that shouldnt
happen.

The power is coming in from a transformer secondary winding that is
center-tapped. Let's call the 3 wires
Line 1, the neutral & Line 2 (seee the link below that shows a
transformer
secondary at the bottom of the page). When you put 120V loads across
Line
1 & neutral, they are independent of Line 2. In effect, you're only
using
half of the transformer secondary, so you're only going thru the Line 1
half of the main breaker. The current path is from the Line 1 side of
the
secondary winding, thru the Line 1 side of the main breaker, thru the
load, and back thru the neutral to the Line 1 half of the secondary
winding.

Agree.

If you also put a 120V load across Line 2 and the neutral, then

the current path is from the Line 2 side of the secondary winding thru
the
Line 2 side of the main breaker, thru the load, and back thru the
neutral
(in the opposite direction of current flow of the Line 1 current thru
the
neutral) and back to the Line 2 side of the secondary winding. Both
loads
form their own circular loops that are independent of each other, except
for sharing the neutral (in opposite directions) to complete their
separate circuits.
Don't agree with this. * *If the second load on line 2 is equal to the
load already on line 1, then the current flow is in on line 1 and back
out on line 2. *No current flows in the neutral.

OK, you're right. If they're perfectly balanced. So lets make the Line
1-to-neutral load
a 200A load (0.6 ohms), and the Line 2-to-neutral load 199A (0.603 ohms).
Now we have an unbalanced current of
1 amp thru the neutral.So we have 200A thru one side of the breaker, and
199A thru the other side. So what's the total amperage now?? Is it 200A or
399A, or? *It's all in how you look at it.

No, it not. Once again, the physical current in the service cable is
200 amps. You have 200 amps flowing IN on one hot, 199 flowing OUT
on the other hot and 1 amp flowing OUT on the neutral. The current
flowing in that circuit is 200 amps. You don't count current twice.

How much current is flowing in a simple 120W light bulb plugged into a
120Volt outlet? 1 amp. Now simply add another single wire in
parallel with one of those supplying the light bulb. The current
will be split now, with some part of it going via one wire, some via
the other. For sake of argument, let;s assume it just splits
evenly. So, now you have 1 amp coming in on one wire, 1/2 amp
leaving via one wire, 1/2 amp leaving via the second wire. How much
current is flowing in this "service" circuit to the light bulb?
There is no confusion, it's 1 amp.

It's a simple matter of applying Kirchoffs law.


In the end ,it's a matter of
total energy or kW.
200A x 120V=24000W & 199A x 120V= 23880W for a total of *47880W or 47.88kW

The key here is look at that service cable coming from the transformer
and you have a circuit running a max of 200 amps. * *Agree?

With a perfectly balanced load - yes, one circuit. With a slightly
unbalanced load - then, two circuits.- Hide quoted text -

- Show quoted text -

Balanced or unbalanced matters not a wit. There is still a current
of 200 amps coming and going either way. The only difference balance
makes is which PATH that 200 amp current takes.